• Geomechanics and Engineering
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• 제12권6호
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• pp.871-882
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• 2017

Indirect measure of the tensile strength of laboratory samples is an important topic in rock engineering. One of the most important tests, the Brazilian strength test is performed to obtain the tensile strength of rock, concrete and other quasi brittle materials. Because the measurements are provided indirectly and the inspected rock materials may have heterogeneous properties, uncertainty quantification is required for a reliable test evaluation. In addition to the conventional measurement evaluation uncertainty methods recommended by the Guide to the Expression of Uncertainty in Measurement (GUM), such as Taylor's and Monte Carlo Methods, a fuzzy set-based approach is also proposed and resulting uncertainties are discussed. The results showed that when a tensile strength measurement is measured by a laboratory test, its uncertainty can also be expressed by one of the methods presented.

• 한국수학교육학회지시리즈A:수학교육
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• 제49권4호
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• pp.395-410
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• 2010

Current mathematics of CSAT(College Scholastic Ability Test) faces time to prepare examination questions according to the new curriculum making this year the last. MEST(Minister of Education, Science and Technology) already decided the range of examination in 2008. However, the discuss about how to construct the questions and what form of questions should be set was not conducted enough. Mathematics items of CSAT will have to undergo changes both in 2012 and 2014. Also, reconstruction of the examination questions for the past 16 years and the exploration of the new direction are strongly required. To accord with these requirements, this study analyze Japan's college entrance exam, NCTUA(National Center Test for University Admissions) which is the most similar to our exams. And then on the basis of this, the applicable implication to set mathematics questions in 2012 and 2014 CSAT will be deducted.

• 한국농공학회지
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• 제24권2호
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• pp.67-75
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• 1982

A study on the effect of water reducing agent on the various characteristics of concrete has been conducted. The experimental results of the study are summarized as follows. 1. Slump test for the concrete added water reducing setretarding agent in proper quantity have been conducted. According to the test results, the decreasing rate of slump value become bigger than plain concrete with increase of the unit weight of cement and elapse of time 2. In case the proper quantity content of maximum compressive strength in Fig. 5 of water reducing set retarding agent is added, unit weight of water is decreased about 15% or so as compared with plain concrete. with the increase of water reducing set accelerating agent content unit weight of water is decreased much more, And other hand, amount of air entraining shows the increasing tendency with the increase of water reducing agent content. 3. The adding rate of water reducing agent which produce maximum strength shows that WR-CH and WR-SA which is water reducing set-starding agent is 0.2% and WR-CO is 0.5% and that WS-PO which is water reducing set accelerating agent is 0.5 4. compressive strength jof the concrete made of sulfate resistant cement shows less than the strength of normal portland cement at initial strength but the strength of both cement shows almost same at curing age of 28 days. 5. when proper quantity of water reducing set retarding agent is used, boned strength is increased about 15% at curing age of 28days. 6. According to the result of durability test, dynamic young's mudulus of elasticity at plain concrete is decreased about 50% as compared with initial step at 300 cycle of freezing and thawing after curing age of days. on the contarary the concrete used water reducing agent is decreased less than 7%.

• Interdisciplinary Bio Central
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• 제3권4호
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• pp.15.1-15.11
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• 2011

Background: Histone deacetylase (HDAC) 8 is one of its family members catalyzes the removal of acetyl groups from N-terminal lysine residues of histone proteins thereby restricts transcription factors from being expressed. Inhibition of HDAC8 has become an emerging and effective anti-cancer therapy for various cancers. Application computational methodologies may result in identifying the key components that can be used in developing future potent HDAC8 inhibitors. Results: Facilitating the discovery of novel and potential chemical scaffolds as starting points in the future HDAC8 inhibitor design, quantitative structure-activity relationship models were generated with 30 training set compounds using genetic function approximation (GFA) and Bayesian algorithms. Six GFA models were selected based on the significant statistical parameters calculated during model development. A Bayesian model using fingerprints was developed with a receiver operating characteristic curve cross-validation value of 0.902. An external test set of 54 diverse compounds was used in validating the models. Conclusions: Finally two out of six models based on their predictive ability over the test set compounds were selected as final GFA models. The Bayesian model has displayed a high classifying ability with the same test set compounds and the positively and negatively contributing molecular fingerprints were also unveiled by the model. The effectively contributing physicochemical properties and molecular fingerprints from a set of known HDAC8 inhibitors were identified and can be used in designing future HDAC8 inhibitors.

• 한국항행학회논문지
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• 제23권5호
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• pp.339-344
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• 2019

정보통신 기술 발전에 따른 데이터 보안 위협의 상승에 대비하기 위하여 유도탄 점검 장비에 저장된 자료의 안전성을 보장할 수 있는 기술은 중요하다. 이를 위하여 자료가 누출 되더라도 복원할 수 없게 데이터 저장 시 암호화를 수행하여야 하고, 해당 데이터를 복호화한 후에도 무결성이 보장되어야 한다. 본 논문에서는 데이터 저장 시 대칭키 암호시스템인 AES 알고리즘을 유도탄 점검장비에 적용하고, 각 AES의 각 비트 별 데이터 양에 따른 암호화 복호화 시간을 측정하였다. 또한 기존 점검 시스템에 AES Rijndael 알고리즘을 구현하여 암호화 수행으로 인한 영향을 분석하였고 제안한 암호화 알고리즘을 기존 시스템에 적용하는 것이 적합한지 확인 하였다. 용량별 / 알고리즘 비트수별로 분석한 결과 제안한 알고리즘 적용이 시스템 운용에 영향 없음을 확인하였고, 최적의 알고리즘을 도출할 수 있었다. 추가로 복호화 결과를 초기 데이터와 비교하였고, 해당 알고리즘이 데이터 무결성을 보장할 수 있음을 확인할 수 있었다.

• Advances in nano research
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• 제12권2호
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• pp.197-212
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• 2022

The purpose of this study is to develop an automatic software system for bone age evaluation and to evaluate its accuracy in testing and feasibility in clinical practice. 20394 left-hand radiographs of healthy children (2-18 years old) were collected from China Skeletal Development Survey data of 1998 and China Skeletal Development Survey data of 2005. Three experienced radiologists and China-05 standard maker jointly evaluate the stages of bone development and the reference bone age was determined by consensus. 1020 from 20394 radiographs were picked randomly as test set and the remaining 19374 radiographs as training set and validation set. Accuracy of the automatic software system for bone age assessment is evaluated in test set and two clinical test sets. Compared with the reference standard, the automatic software system based on RUS-CHN for bone age assessment has a 0.04 years old mean difference, ±0.40 years old in 95% confidence interval by single reading, a 85.6% percentage agreement of ratings, a 93.7% bone age accuracy rate, 0.17 years old of MAD, 0.29 years old of RMS; Compared with the reference standard, the automatic software system based on TW3-C RUS has a 0.04 years old mean difference, a ±0.38 years old in 95% confidence interval by single reading, a 90.9% percentage agreement of ratings, a 93.2% bone age accuracy rate, a 0.16 years of MAD, and a 0.28 years of RMS. Automatic software system, AI-China-05 showed reliably accuracy in bone age estimation and steady determination in different clinical test sets.

• 대한방사선치료학회지
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• 제30권1_2호
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• pp.97-105
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• 2018

목 적 : Proton Therapy는 Bragg-peak를 이용해 종양에는 최대의 선량, 정상조직에는 최소의 선량을 줄 수 있는 특징을 가지고 있기 때문에 환자의 위치변화나 치료부위의 위치 변화를 정량화 할 수 있는 의료영상 분석 시스템은 양성자 치료에 있어서 무엇보다도 중요하다. 본 연구 목적은 Matlab 기반의 In-house Registration code를 제작하여 기존 DIPS program을 통한 Set-up과 In-house code를 통한 영상정합을 비교하여 Algorithm의 유용성을 평가하고 DIPS와 DRR간의 오차 값을 확인하여 기존 치료의 정확성을 평가하고자 한다. 대상 및 방법 : 본원에서 양성자 치료를 받은 13명의 뇌종양, 두경부암 환자를 대상으로 하였으며 영상비교에 필요한 DIPS Program System(Version 2.4.3, IBA, Belgium)와 환자의 치료계획을 위해 Eclipse Proton Planning System(Version 13.7, Varian, USA)을 사용하였다. Registration 방법에 대한 Validation을 위해 Test image를 인위적으로 회전 및 이동하여 기존 Image와 영상정합 하였고, 기존 Set up 방식의 DIPS program의 환자 일별 초기 Set up image를 plan DRR과 영상정합 하여 각각 오차 값을 얻어 Algorithm의 유용성을 평가하였다. 그리고 기존 Set up 방식의 정확성을 평가하기 위해 환자 일별 최종 Set up image와 DRR image를 영상정합하여 오차 값을 확인하였다. 결 과 : Test image를 left와 right 방향으로 각각 0.5, 1, 10 cm를 이동시켰을 때 평균 0.018 cm의 오차 값을 보였으며 시계와 반시계방향으로 각각 1, $10^{\circ}$씩 회전시켰을 경우에는 평균 $0.0011^{\circ}$의 오차를 나타냈다. 4명의 환자 일별 초기 image를 영상정합 하였을 때는 x, y, z 방향 순으로 평균 0.056, 0.044, 0.053 cm의 오차 값을 나타냈으며 Rotation, Pitch 순으로 0.190, $0.206^{\circ}$의 차이를 나타냈다. 13명의 환자 일별 최종 image를 영상 정합 하였을 때는 x, y, z 방향 순으로 평균 차이는 0.062, 0.085, 0.074 cm이였고 Vector 값으로는 평균 0.120 cm의 차이를 보였다. Rotation, Pitch 순으로는 평균 0.171, $0.174^{\circ}$의 차이 값을 나타냈다. 결 론 : 본 연구를 통해 제작된 Matlab 기반의 In-house Registration code는 단순한 Image 뿐만 아니라 해부학적 구조에서도 Intensity 기반의 정확한 영상정합을 나타냈다. 또한 기존 치료방식의 DIPS program을 통한 Set-up 오차는 매우 미미한 차이를 보임으로써 이는 양성자치료의 정확성을 확인할 수 있었다. 앞으로 임상적용을 위해 추가적인 프로그램 개발과 향후 Intensity 기반의 Matlab In-house code 연구가 필요하다고 사료된다.

• 대한영양사협회학술지
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• 제13권1호
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• pp.1-14
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• 2007

The purpose of this study was to assess students’ preference on set menus served in school foodservice. Questionnaires were distributed to 4,050 students enrolled in 34 middle and high schools located in Seoul, Gyeonggi, and Gyeongnam provinces. The students were asked to assess their preferences on 78 set menus using a 5-point Likert-type scale(1 : very dislike - 5 : very like). Excluding responses with significant missing data, usable responses were 3,433. Data were analyzed with descriptive analysis, t-test, and one-way analysis of variance. There was no difference between middle and high school students in terms of set menu preferences. On the other hand, there was significant difference between boys' and girls' set menu preferences. Among the seven given set menu groups(rice and soup with side dishes, tangs, rice with toppings, fried rice, western foods, noodles.ddeokguk.dumpling soups, and bibimbaps), boys had higher preference scores for the rice and soup with side dishes, tangs, rice with toppings, and fried rice than that of girls. Fried rice set menus were chosen to be boys’ favorite menus while western food set menus were most preferred by the girls. Rice and soup with side dishes set menus were least preferred by both boys and girls.

• 한국통신학회논문지
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• 제19권11호
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• pp.2255-2263
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• 1994

프로토콜 적합성 시험은 시험 대상인 구현물을 하나의 black box로서 고려하여 input에 대한 output 과 결과 상태를 확인하는 일련의 과정으로 구성된다. 특히 결과 상태를 확인하는 방법에 따라 Unique Input/Output(UIO) Sequence, Distinguishing Sequence(DS) 및 Characterization Set(CS) 등으로 구분할 수 있다. 또한 UIO sequence가 존재하지 않는 상태에 대한 시험을 위해서라고 Partial UIO Set(CS) 등으로 구분 할 수 이따. 또한 PUIO sequence가 존재하지 않는 상태에 대한 시험을 위해서도 Partial UIO sequence 방법이 제안되었다. 본 논문에서는 이러한 PUIO sequence를 제시하고 이를 이용한 개선된 PUIO sequence 제안하였으며, 그 적용 결과로서 PUIO sequence의 수가 56%정도 줄어드는 것을 확인할 수 있었다.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.613-619
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• 2012

We applied several machine learning methods for developing QSAR models for prediction of acute toxicity to fathead minnow. The multiple linear regression (MLR) and artificial neural network (ANN) method were applied to predict 96 h $LC_{50}$ (median lethal concentration) of 555 chemical compounds. Molecular descriptors based on 2D chemical structure were calculated by PreADMET program. The recursive partitioning (RP) model was used for grouping of mode of actions as reactive or narcosis, followed by MLR method of chemicals within the same mode of action. The MLR, ANN, and two RP-MLR models possessed correlation coefficients ($R^2$) as 0.553, 0.618, 0.632, and 0.605 on test set, respectively. The consensus model of ANN and two RP-MLR models was used as the best model on training set and showed good predictivity ($R^2$=0.663) on the test set.